TY - JOUR
T1 - Electron attachment to SF6 in gaseous Ar and Xe; comparison to results in liquid Ar and Xe and energy of excess electrons
AU - Christophorou, L. G.
AU - Hunter, S. R.
AU - Carter, J. G.
PY - 1989
Y1 - 1989
N2 - The total electron attachment rate constant for SF6 measured by us in gaseous Ar and Xe over an extended energy range is compared with that measured by others in liquid Ar and Xe. A similar comparison is made for the electron transport coefficients. The thermal value of the total electron attachment rate constant for SF6 in gaseous, (ka)G,th, and in liquid, (ka)L,th, argon are virtually identical and both are ~3 times smaller than the maximum s-wave thermal rate constant, (ka)s-wave,th. The (ka)L,th for SF6 in liquid xenon is ~3 times larger than (ka)G,th and comparable to (ka)s-wave,th. These data are rationalized by considering the total energy ET available for the reaction eliquid + SF6liquid → SF-*6liquid. From a comparison of the (ka)G and (ka)L as functions of the density-normalized electric field E/N and from a knowledge of the mean electron energy 〈ε{lunate}〉G as a function of E/N in gaseous Ar and Xe, a mean electron energy scale 〈ε{lunate}〉 vs E/N has been established for liquid Ar and liquid Xe. The 〈ε{lunate}〉L vs E/N determined in this work is compared with theoretical estimates; it allows a plot of (ka)L vs 〈ε{lunate}〉L for SF6 in liquid Ar and liquid Xe. Detailed comparisons are also given of the electron drift velocity wG(E/N) in gaseous Ar and Xe, and wL(E/N) in liquid Ar and Xe, and the mean electron energy 〈ε{lunate}〉G(E/N) in gaseous and 〈ε{lunate}〉L(E/N) in liquid Ar and Xe.
AB - The total electron attachment rate constant for SF6 measured by us in gaseous Ar and Xe over an extended energy range is compared with that measured by others in liquid Ar and Xe. A similar comparison is made for the electron transport coefficients. The thermal value of the total electron attachment rate constant for SF6 in gaseous, (ka)G,th, and in liquid, (ka)L,th, argon are virtually identical and both are ~3 times smaller than the maximum s-wave thermal rate constant, (ka)s-wave,th. The (ka)L,th for SF6 in liquid xenon is ~3 times larger than (ka)G,th and comparable to (ka)s-wave,th. These data are rationalized by considering the total energy ET available for the reaction eliquid + SF6liquid → SF-*6liquid. From a comparison of the (ka)G and (ka)L as functions of the density-normalized electric field E/N and from a knowledge of the mean electron energy 〈ε{lunate}〉G as a function of E/N in gaseous Ar and Xe, a mean electron energy scale 〈ε{lunate}〉 vs E/N has been established for liquid Ar and liquid Xe. The 〈ε{lunate}〉L vs E/N determined in this work is compared with theoretical estimates; it allows a plot of (ka)L vs 〈ε{lunate}〉L for SF6 in liquid Ar and liquid Xe. Detailed comparisons are also given of the electron drift velocity wG(E/N) in gaseous Ar and Xe, and wL(E/N) in liquid Ar and Xe, and the mean electron energy 〈ε{lunate}〉G(E/N) in gaseous and 〈ε{lunate}〉L(E/N) in liquid Ar and Xe.
UR - http://www.scopus.com/inward/record.url?scp=50849146914&partnerID=8YFLogxK
U2 - 10.1016/1359-0197(89)90291-9
DO - 10.1016/1359-0197(89)90291-9
M3 - Article
AN - SCOPUS:50849146914
SN - 1359-0197
VL - 34
SP - 819
EP - 827
JO - International Journal of Radiation Applications and Instrumentation. Part
JF - International Journal of Radiation Applications and Instrumentation. Part
IS - 5
ER -